Whole-life costs: Height of offices | Features

Base building, air-conditioned office
Basic information
Gross internal floor area: 12,000 m2
Construction: Steel frame of 44 kg/m2
Substructure: 200 mm ground-bearing slab
Roof: Pitched, Sarna single membrane proprietary roofing system with parapets
External walls: Mostly wall cladding with reconstituted stone. 20% is polyester powder-coated aluminium curtain walling, fully glazed to clear height with double-glazed low-emissivity glass
Window frames: Aluminium
Windows: Double-glazed, low-emissivity glass
Air conditioning: Fan-coil units
Lifts: Three passenger and two goods
Capital costs (£)
Substructure	1,254,442
Structure	1,858,812
External envelope	2,508,503
Internal divisions	857,634
Finishings and fittings	2,937,021
Mechanical	4,453,039
Electrical & communications	2,049,543
Lifts	665,672
Preliminaries, overheads and profit	2,321,853
Design risk and contingency	1,133,909
Total	20,040,909
Net present costs for energy consumption (£)*
Space heating	5,852
Cooling and fans	24,560
Lighting	19,403
Other energy costs	38,147
Annual total	87,962
Net present cost (over 30 years)	1,617,786**
Net present cost of repair and maintenance costs over 30 years (£, limited to the main elements that change the most)
Roof coverings	202,761
Roof edge and parapet gutter	8,817
Wall cladding	25,619
Curtain walling	38,951
Windows and bris soleil	103,811
Lifts	327,141
Total net present cost	707,200
* It is normal to use the same discount rate for all operating costs. However, energy costs are expected to rise more than general inflation, so if we were to use a 2% lower discount rate of 1.5%, the net present cost for energy would be 30.6% higher at £2,112,470.
** Discounted at 3.5%.